01594221

Component

Double queue concept has recently been applied in continuous-time dynamic user assignment (DUE) because it can capture queue spillbacks by presenting link dynamics with capacitated upstream and downstream queues. While directly solving such DUE problems with time-varying, state-dependent delays is extremely challenging, some approximation schemes (called first-order approximation technique in this paper) have been proposed to simplify the link travel time calculation in a recent study on double-queue-based continuous-time DUE model. This paper mainly focuses on analyzing the performance and the properties of such approximated travel times. It is proved that with the first-order approximation, FIFO is guaranteed for network with fixed link capacities but may be violated if link capacities are time-varying. Numerical analysis is conducted on a simple stretch network with travel times computed based on accumulative inflow and exit flow curves, point queue model, the second-order approximation for comparison. The results state that if the demand is larger than the link capacities, the first-order approximation techniques lead to either overestimated or underestimated link travel times. In addition, overall the double queue model can produce relatively higher performance than the point queue model and the second-order approximated results are slightly better than the first-order approximated results.

This paper was sponsored by TRB committee AHB45 Standing Committee on Traffic Flow Theory and Characteristics.

01584066

16-5885

English

17p

2016

Transportation Research Board 95th Annual Meeting

Digital/other

Figures; References; Tables

Approximation (Mathematics); Dynamic traffic assignment; Network analysis (Planning); Queuing theory; Traffic models; Travel time

Data and Information Technology; Highways; Planning and Forecasting

Transportation Research Board Annual Meeting 2016 Paper #16-5885

TRIS, TRB, ATRI

Jan 12 2016 6:36PM